This script was made to emulate a station migration scenario, in a heterogeneous controller environment, using Mininet-Wifi.

heterogeneous_controller_station_migration.py

#!/usr/bin/python
"""
This script is used to emulate a scenario where
a station migrates from one AP to another, while 
attempting to ping a station from the third AP.
Controllers used to test: ODL, FL, Ryu.
Emulator used: Mininet-Wifi

Initial state
-------------

AP1              AP3
 |                |
sta1.............sta3



AP2

Final state
-----------

AP1              AP3
                  |
                 sta3
                 .
             .../
          ../
AP2   .../
 | ../
sta1
"""

from mininet.node import Controller, RemoteController
from mininet.log import setLogLevel, info
from mn_wifi.net import Mininet_wifi
from mn_wifi.node import Station
from mn_wifi.cli import CLI
from mn_wifi.link import wmediumd
from mn_wifi.wmediumdConnector import interference


def network_init():
    # Setting initial network config
    net = Mininet_wifi(
        topo=None,
        build=False,
        link=wmediumd,
        wmediumd_mode=interference,
    )

    info("*** Adding controller\n")
    c0 = net.addController(
        name="c0", controller=RemoteController, ip="192.168.0.122", protocols="tcp", port=6653
    )
    c1 = net.addController(
        name="c1", controller=RemoteController, ip="192.168.0.141", protocols="tcp", port=6653
    )
    c2 = net.addController(
        name="c2", controller=RemoteController, ip="192.168.0.217", protocols="tcp", port=6633
    )

    info("*** Add switches/APs\n")
    ap1 = net.addAccessPoint(
        "ap1", ssid="ap1-ssid", channel="1", mode="g", position="270,339,0"
    )
    ap2 = net.addAccessPoint(
        "ap2", ssid="ap2-ssid", channel="2", mode="g", position="790,340,0"
    )
    ap3 = net.addAccessPoint(
        "ap3", ssid="ap3-ssid", channel="3", mode="g", position="270,1039,0"
    )

    info("*** Add hosts/stations\n")
    sta1 = net.addStation("sta1", ip="192.168.0.29", position="300,400,0")
    sta2 = net.addStation("sta2", ip="192.168.0.25", position="300,300,0")
    sta3 = net.addStation("sta3", ip="192.168.0.35", position="700,470,0")
    sta4 = net.addStation("sta4", ip="192.168.0.28", position="700,500,0")
    sta5 = net.addStation("sta5", ip="192.168.0.26", position="300,1000,0")

    net.configureWifiNodes()

    info("*** Add links\n")
    net.addLink(ap1, sta1)
    net.addLink(ap1, sta2)
    net.addLink(ap2, sta3)
    net.addLink(ap2, sta4)
    net.addLink(ap3, sta5)
    net.addLink(ap1, ap2)
    net.addLink(ap1, ap3)

    info("*** Mobility\n")
    p1, p2 = dict(), dict()
    p1 = {"position": "300, 1000, 0"}
    p2 = {"position": "270, 300, 0"}

    net.startMobility(time=0, AC="ssf")
    net.mobility(sta5, "start", time=1, **p1)
    net.mobility(sta5, "stop", time=60, **p2)
    net.stopMobility(time=60)

    net.plotGraph(max_x=1000, max_y=1000)

    info("*** Starting network\n")
    net.build()

    info("*** Starting controllers\n")
    for controller in net.controllers:
        controller.start()

    info("*** Starting switches/APs\n")
    net.get("ap1").start([c0, c1, c2])
    net.get("ap2").start([c0, c1, c2])
    net.get("ap3").start([c0, c1, c2])

    info("*** Post configure nodes\n")

    CLI(net)
    net.stop()


if __name__ == "__main__":
    network_init()